Well, one hopeful thought - they have no qualms about killing off kids on this show so there's hope that Carl and Lori along with her unborn zombie all get the axe.

If the CDC guy told Rick that the virus was airborne and there was no hope, then why would Rick even bother trying to save everyone? I would have told the whole crew and let them decide how they wanted to die. My choice would have been to get blown up in the CDC explosion.